JP2003320801A - Wheel for motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve productivity by easily casting a wheel by a metallic mold on one side surface side of the wheel and a metallic mold on the other side surface side without using a core like a conventional way. <P>SOLUTION: A hub part 65 is constituted of an inner hub 81 arranged on an axle 50 side, an outer hub 82 connected to a spoke part 66 arranged on an outer peripheral side of the inner hub 81, and side walls 71 and 75 for integrally connecting the inner hub 81 and the outer hub 82. First recessed part 73 and second recessed part 77 recessed in a shaft direction between the inner hub 81 and the outer hub 82 and having first openings 78 and 79 and first bottom walls 73A and 77A formed on opposite sides to each other are arranged alternately in a circumferential direction. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle wheel having improved wheel productivity, reduced weight, and improved quality.

[0002]

2. Description of the Related Art As a wheel for a motorcycle, for example, Japanese Patent Laid-Open No. 11-59108, "Front Wheel for Motorcycle" is known. 21 and 22 of the above publication will be described with reference to FIGS. 10 (a) and 10 (b) below. Note that the reference numerals have been reassigned.

FIGS. 10 (a) and 10 (b) are views for explaining a conventional motorcycle wheel, and FIG.
1 (front view) and (b) of FIG. 22 ((a) of the same publication).
It is a sectional view taken along line A). In (a), the front wheel 100 includes a hub portion 101 for mounting on an axle and a spoke portion 102 extending radially outward from the hub portion 101.
... (... indicates a plurality, the same applies hereinafter) and the cylindrical rim portion 10 connected to the respective tips of the spoke portions 102.
3 and 3.

In FIG. 1B, the hub portion 101 includes an inner hub 104 on the axle side, an outer hub 105 arranged radially outside of the inner hub 104, and the inner hub 1 thereof.
04 and the outer hub 105, the left side wall portion 106 and the right side wall portion 107 are connected to each other. The outer hub 105 is provided with bolt boss portions 108 for attaching brake discs to both ends, and an opening 111 for holding a core during casting.

[0005]

In (a) and (b), in the above-described front wheel 100, for example, the hub portion 101 is cast using a core, and therefore, in addition to the molding of the core itself, The man-hours for pressing the core, discharging the core, and closing the opening 111 are required, which lowers the productivity.

In the case where the front wheel 100 is to be cast by a die on one side of the front wheel 100 and a die on the other side without using a core,
The space between the bolt bosses 108, 108 cannot be removed with the above-mentioned mold, so that the excess thickness increases and the weight increases. Further, if the surplus thickness is large, the wall thickness may not be partially constant, the flow of the molten metal during casting becomes unstable, and the quality of the casting material may be deteriorated.

Therefore, an object of the present invention is to improve wheel productivity for a motorcycle by improving the wheel for a motorcycle, and further, to reduce the weight and improve the quality.

[0008]

In order to achieve the above object, the first aspect of the present invention is a motorcycle comprising a hub portion rotatably supported by an axle and a rim portion connected to the hub portion via spoke portions. In the vehicle wheel, the hub portion includes an inner hub arranged on the axle side, an outer hub arranged on the outer peripheral side of the inner hub and connected to a spoke portion, and a connecting portion integrally connecting the inner hub and the outer hub. A recess is formed in the axial direction between the outer hub and an opening and a bottom are formed on opposite sides of each other.
It is characterized in that the concave portions of the seed are alternately arranged in the circumferential direction.

By arranging the two kinds of recesses alternately in the circumferential direction, the wheel can be formed by the mold on one side surface side and the mold on the other side surface side without using a core as in the prior art. Can be easily cast, and productivity can be improved.

A second aspect of the present invention is characterized in that a thick boss portion is formed on the bottom wall of the recess. By forming a thick boss portion on the bottom wall, the boss portion provided on one side wall and the boss portion provided on the other side wall do not overlap in the axial direction of the hub portion. When a wheel is cast from the mold on the side of and the mold on the side of the other side, the boss portion provided on one side wall of the hub portion and the boss portion provided on the other side wall of the hub portion are overlapped with each other as in the conventional case. When placed in
In contrast to the large surplus formed between the boss portions, the present invention allows the recess to be deepened to reduce the surplus thickness, thereby making the wheel lightweight. If the boss portion is thick, the length of the bolt hole formed in the boss portion for attaching the component to the boss portion can be increased, and the component can be attached to the boss portion more firmly.

A third aspect of the invention is characterized in that the two kinds of recesses are tapered from the bottom to the opening. By tapering the recess, the wall thickness of the bottom of the recess can be increased, and when a boss for mounting components is provided on this bottom, the boss can be made thicker and the mounting of components Strength can be increased.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of the reference numerals. FIG. 1 is a side view of a motorcycle provided with a wheel according to the present invention. A motorcycle 10 includes a front fork 12 steerably attached to a head pipe 11,
A front wheel 13 rotatably attached to the lower end of the front fork 12, a main frame 14 extending obliquely rearward and downward from the head pipe 11, and a swing arm 15 swingably attached to the rear portion of the main frame 14,
A rear cushion 16 having a rear wheel 16 rotatably attached to the rear end of the swing arm 15, an upper end attached to an upper front portion of the swing arm 15, and a lower end connected to a lower rear portion of the main frame 14 and a lower portion of the swing arm 15. The unit 17, the engine 18 attached to the lower part of the main frame 14, the muffler 21 connected to the engine 18 via an exhaust pipe, the fuel tank 22 attached to the upper part of the main frame 14, and the rear of the fuel tank 22. The sheets 23 and 24 arranged in the.

The front wheel 13 comprises a front wheel 31 and a tire 32 mounted on the front wheel 31, and the rear wheel 16 comprises a rear wheel 33 and a tire 34 mounted on the rear wheel 33. In addition, 36 is a front disc brake, and the brake caliper 3
7 and two brake discs 38 and 41 (the rear brake disc 41 is not shown). Reference numeral 43 denotes a rear disc brake, which includes a brake caliper 44 and a brake disc 45.

Here, 50 is an axle of the front wheel 13, 51 is a front fender that covers the front wheel 13 from above, 52 is an upper cowl, 53 is a middle cowl, 54 is a lower cowl, 55 is a side cover, 56 is an axle of the rear wheel 16, 57 is the rear wheel 16
It is a rear fender that covers the upper part of the.

FIG. 2 is a side view of the front wheel according to the present invention. The front wheel 31 is the axle 50 (see FIG. 1).
Hub portion 65 for attaching to the
Of the tires 32 extending substantially radially outward from the tires 32 and attached to the tips of the spokes 66.
(See FIG. 1).

3 (a) and 3 (b) are side views showing the hub portion of the wheel according to the present invention. FIG. 3 (a) is a left side view of the hub portion 65 and FIG. 3 (b) is a right side surface of the hub portion 65. It is a figure.
In (a), the hub portion 65 has a boss portion 72 for mounting the brake disc 38 (see FIG. 1) and a first recess 73 on substantially the same circumference on one side wall 71 as a connecting portion. The portions are formed alternately. Each boss 72
Are, for example, arranged at equal intervals of 60 ° in the circumferential direction, and the respective first recesses 73 are arranged at equal intervals of 60 ° in the circumferential direction, separated by 30 ° from each boss portion 72. In addition, 7
Denoted at 4 are bolt holes into which bolts (not shown) for attaching the brake disc 38 to the bosses 72 are screwed.

In (b), the hub portion 65 has a boss portion 76 for mounting the brake disc 41 (not shown) on the other side wall 75 as a connecting portion, and a second recess 77.
And are formed alternately on the circumference. The second recesses 77 are arranged at equal intervals of 60 ° in the circumferential direction, and the bosses 76 are spaced at 30 ° from the second recesses 77 and are arranged at equal intervals of 60 ° in the circumferential direction. Is.

In the above (a) and (b), the boss portion 76
Are arranged just behind the first recesses 73, and the second recesses 77 are arranged just behind the bosses 72.

FIG. 4 is a sectional view taken along the line 4-4 in FIG. 2. The hub portion 65 has a cylindrical inner hub 81 provided on the axle 50 side.
And a cylindrical outer hub 82 provided radially outside of the inner hub 81, and the side walls 71, 75 for connecting both ends of the inner hub 81 and the outer hub 82, respectively.
The outer hub 82 and the spoke portions 66 are integrally formed.

The above-mentioned first recess 73 and second recess 77 are
It is formed between the inner hub 81 and the outer hub 82, and the boss portion 76 is formed on the first bottom wall 73A as the bottom portion of the first recess 73, and the second boss as the bottom portion of the second recess 77.
The boss portion 72 is formed on the bottom wall 77A. 78 is the first
The first opening as an opening of the recess 73, 79 is the second recess 7
7 is a second opening as an opening.

The boss portions 72 and 76 are portions where the aforementioned bolt holes 74 are formed. The first recess 73 is the first
This is a portion that is tapered from the bottom wall 73A to the first opening 78, the taper angle is θ1 (the draft of the mold is θ1 / 2), and similarly, the second recess 77 is the second. Bottom wall 7
7A, which is a portion that tapers into the second opening 79,
The taper angle is θ2 (the draft of the mold is θ2 / 2). The taper angle θ1 and the taper angle θ2 may be the same or different. The structure of the rear wheel 33 shown in FIG. 1 is basically the same as that of the front wheel 31 described above, and the description thereof will be omitted.

FIGS. 5A and 5B are sectional views of the boss portion in the circumferential direction. 5A is a sectional view taken along line 5-5 of FIG. 3A (embodiment of the present invention), showing that first recesses 73 and second recesses 77 are alternately arranged in the circumferential direction. Assuming that the taper angle θ1 and the taper angle θ2 shown in FIG. 4 are θ1 = θ2, the first concave portion 73 and the second concave portion 77 in FIG.
The wall thickness t of the partition wall 65A as a connecting portion between and can be made substantially constant. If the wall thickness t is constant, the wall thickness t can be made as small as possible within the range where the required strength can be obtained, and the weight can be reduced.

Further, by making the wall thickness t constant, as will be described later, the molten metal can be stably flown into the cavity during casting, and a uniform casting material can be produced, so that the quality of the casting material is improved. Can be improved, and the quality of the front wheel 31 (see FIG. 4) can be improved.

(B) is a comparative example, and shows that the recessed portions 115 ... Which are recessed in the extending direction of the wheel axle are formed from only one side surface of the hub portion. Incidentally, 116 is the other side surface of the hub portion. When the wall thickness t shown in the embodiment (a) is drawn by an imaginary line in the wall 117 between the recessed portions 115, 115, the cross-hatched portion increases in weight as a thick portion. That is, since the recess 15 has a draft, the wall thickness t1 of the wall 117 on the bottom 118 side of the recess 15 becomes large.

Further, since the wall thickness of the wall 117 is not constant, when the molten metal is flown into the cavity during casting, the flow of the molten metal changes between the thick portion and the thin portion, so that the molten metal flows. It is not stable and it is difficult to improve the quality of the wheel.

A method of manufacturing the above-mentioned front wheel will be described below. 6 (a) and 6 (b) are first operation diagrams showing the wheel manufacturing method according to the present invention. In (a), a casting die 90 for a front wheel includes a first die 91 that forms one side surface of the front wheel, a second die 92 that forms the other side surface of the front wheel, and a rim of the front wheel. Third die 93 forming the outer peripheral surface of the portion
Consists of. Although the third mold 93 is composed of a plurality of split molds, it will be described here as one mold. In addition, 91A
Is a projection for forming the first recess 73 (see FIG. 4), 9
2A is a convex portion for forming the second concave portion 77 (see FIG. 4).

First, the cavity 95 for casting the front wheel is formed by combining the first die 91, the second die 92 and the third die 93. Then, the molten metal is injected into the cavity 95 by an injection device (not shown), and (b)
As shown in, the molten metal 96 is filled in the cavity 95,
Cooling.

FIG. 7 is a second operational view showing the method for manufacturing a wheel according to the present invention, and the manufacturing method is shown following the first operational view. Molten metal 9 in the cavity 95 (see FIG. 5 (a))
After 6 (see FIG. 5B) is solidified, the casting die 90 is unmolded, and the casting material 97 for the front wheel is taken out. This completes the molding of the casting material 97 for the front wheel. Then, a part of the casting material 97 is ground to complete the front wheel 31 (see FIG. 4). As described above, in the casting die 90 of the present invention, the casting material 97 can be easily formed without using the core.

Further, as described above, in the present invention, the first recess 73 and the second recess 77 are alternately arranged in the circumferential direction, so that the partition wall 65A between the first recess 73 and the second recess 77 is formed.
The thickness t can be made constant, the flow of the molten metal at the time of casting can be stabilized, and, for example, the generation of cavities can be suppressed and the quality of the front wheel can be improved.

FIGS. 8 (a) to 8 (d) are views for comparing the structures of the hub portions. FIGS. 8 (a) and 8 (b) are comparative examples, and FIGS.
(D) shows an example (this embodiment). Note that the shape of the hub portion is schematically drawn for convenience. In the comparative example of (a), the hub portion 121 has the boss portion 1 on the side wall 122.
It is a portion in which 23 and concave portions 124 are alternately arranged on the circumference. In addition, 125 is a bolt hole.

(B) is a sectional view taken along line BB of (a),
The boss 128 and the recess 1 are formed on the side wall 127 on the back side of the side wall 122.
31 and 31 are arranged alternately on the circumference. That is, each boss 128 is arranged just behind each boss 123, and each recess 131 is arranged just behind each recess 124.

In the embodiment of (c), the hub portion 65 is
The side wall 71 is a portion in which boss portions 72 and first concave portions 73 are alternately arranged on the circumference. (D) is a sectional view taken along the line D-D of (c), showing that bosses 76 and second recesses 77 are alternately arranged on the circumference on the side wall 75 on the back side of the side wall 71. That is, each boss portion 76 is arranged just behind each first recess 73, and each second boss 77 is arranged just behind each boss 72.

As shown in (b) and (d) above, in the comparative example, since the boss portion 128 is located on the back side of the boss portion 123, a large extra thickness is formed between the boss portions 123 and 128. On the other hand, in the embodiment of the present invention, since the boss portion 76 is arranged on the back side of the first recess 73 and the boss portion 72 is arranged on the back side of the second recess 77, the space between the first recess 73 and the boss portion 76 and The extra thickness between the second recess 77 and the boss 72 can be reduced.

As described above with reference to FIGS. 2 and 4, the first aspect of the present invention is the hub portion 6 which is rotatably supported by the axle 50.
5 and the rim portion 67 connected to the hub portion 65 via the spoke portions 66, in the front wheel 31 as a motorcycle wheel, the hub portion 65 is attached to the axle 5
The inner hub 81 arranged on the 0 side and this inner hub 81
The outer hub 82 arranged on the outer peripheral side of the outer hub 82 and connected to the spoke portions 66, and the side walls 71 and 75 as a connecting portion integrally connecting the inner hub 81 and the outer hub 82, and between the inner hub 81 and the outer hub 82, The first and second openings 78, 79 and the first
It is characterized in that the first recesses 73 and the second recesses 77 in which the second bottom walls 73A and 77A are formed on the opposite sides are alternately arranged in the circumferential direction.

By arranging the first concave portions 73 and the second concave portions 77 alternately in the circumferential direction, the first concave portion on one side surface of the front wheel 31 can be formed without using a core as in the prior art.
The front wheel 31 can be easily cast by the die 91 and the second die 92 on the other side surface side, and the productivity can be improved.

Secondly, according to the present invention, as shown in FIGS. 4 to 6, the first bottom wall 73A and the second bottom wall 77A of the first recess 73 and the second recess 77 are provided for the front disc brake 36. A boss portion 72 for mounting the brake discs 38, 41,
76 is formed.

By forming the boss portions 76 and 72 on the first bottom wall 73A and the second bottom wall 77A, the boss portion 72 provided on one side wall 71 and the boss portion 76 provided on the other side wall 75.
Since and do not overlap in the axial direction of the hub portion 65, for example, the front wheel 31 is cast from the first die 91 on one side surface side of the front wheel 31 and the second die 92 on the other side surface side. In this case, when a boss portion provided on one side wall of the hub portion and a boss portion provided on the other side wall of the hub portion are arranged so as to overlap with each other as in the conventional case, a large extra thickness is formed between the boss portions. In the present invention, the excess thickness can be reduced by making the first recess 73 and the second recess 77 deep.
The front wheel 31 can be made lightweight.

If the bosses 72 and 76 are thick,
The length of the bolt hole 74 for mounting the brake discs 38, 41 and the like on the boss portions 72, 76 can be increased, and the components can be more firmly attached to the boss portions 72, 76.

Furthermore, the wall thickness t of the partition wall 65A between the first concave portion 73 and the second concave portion 77 can be made thin and constant, and the weight can be reduced, and the flow of the molten metal during casting can be achieved. It is possible to stabilize and improve the quality of the front wheel 31.

Further, for example, in the rear wheel 33 shown in FIG. 1, a brake disc 45 for the rear disc brake 43 and a driven sprocket driven by a chain can be attached to the hub portion of the hub portion thereof. .

Thirdly, according to the present invention, two kinds of recesses, a first recess 73 and a second recess 77, are provided.
It is characterized in that it is expanded in a tapered shape from 7A to the first and second openings 78 and 79. By tapering the first recess 73 and the second recess 77, respectively, the first bottom wall 73A and the second bottom wall 73A
The thickness of the bottom wall 77A can be increased, and the boss portion 7 for mounting parts on the first bottom wall 73A and the second bottom wall 77A.
When the two and 76 are provided, the bosses 72 and 76 can be made thicker and the mounting strength of the component can be increased.

FIG. 9 is a cross-sectional view showing another embodiment of the wheel according to the present invention. The front wheel 98 includes a first bottom wall 73A of the first recess 73 and a second bottom wall of the second recess 77. 77A and through holes 99 are formed in each of them. The rest of the configuration is the same as that of the embodiment shown in FIG. The through hole 99 may be formed by a casting mold or may be drilled. Thus, the first recess 7
By making the through holes 99 in the first bottom walls 73A and 77A of the third and second recesses 77, the front wheel 98 can be made lighter.

In this embodiment, the recessed portion of the hub portion and the boss portion are arranged on substantially the same circumference, but the present invention is not limited to this.
The recesses and the bosses may be arranged alternately, and the recesses and the bosses may be arranged on different circumferences (that is, on circles having different diameters).

[0044]

The present invention has the following effects due to the above configuration. The motorcycle wheel according to claim 1 has a hub portion,
It consists of an inner hub arranged on the axle side, an outer hub arranged on the outer peripheral side of this inner hub and connected to the spoke parts, and a connecting part that integrally connects these inner hub and outer hub. Since two kinds of recesses, which are recessed in the opening and the opening and the bottom are formed on opposite sides of each other, are alternately arranged in the circumferential direction, without using a core as in the prior art, one side surface of the wheel can be formed. The wheel can be easily cast by the mold and the mold on the other side surface, and the productivity can be improved.

In the motorcycle wheel of claim 2, since the thick boss portion is formed on the bottom wall of the recess, the boss portion provided on one side wall and the boss portion provided on the other side wall are hubs. Since it does not overlap in the axial direction of the parts, for example, when the wheel is cast from a mold on one side surface of the wheel and a mold on the other side surface, it is provided on one side wall of the hub portion as in the conventional case. When the boss portion and the boss portion provided on the other side wall are arranged so as to overlap with each other, a large surplus is formed between the boss portions, but in the present invention, the surplus is reduced by making the recess deep. The wheels can be made lighter. If the boss portion is thick, the length of the bolt hole formed in the boss portion for attaching the component to the boss portion can be increased, and the component can be attached to the boss portion more firmly.

In the motorcycle wheel of the third aspect, since the two kinds of recesses are tapered from the bottom to the opening, the wall thickness of the bottom of the recess can be increased, and parts are mounted on the bottom. When the boss portion is provided, the boss portion can be made thicker and the mounting strength of the component can be increased.

[Brief description of drawings]

FIG. 1 is a side view of a motorcycle including a wheel according to the present invention.

FIG. 2 is a side view of a front wheel according to the present invention.

FIG. 3 is a side view showing a hub portion of a wheel according to the present invention.

FIG. 4 is a sectional view taken along line 4-4 of FIG.

FIG. 5 is a sectional view of the boss portion in the circumferential direction.

FIG. 6 is a first action diagram showing a wheel manufacturing method according to the present invention.

FIG. 7 is a second action diagram showing the wheel manufacturing method according to the present invention.

FIG. 8 is a diagram comparing structures of hub portions.

FIG. 9 is a cross-sectional view showing another embodiment of the wheel according to the present invention.

FIG. 10 is a diagram for explaining a conventional motorcycle wheel.

[Explanation of symbols]

10 ... motorcycle, 31, 98 ... front wheel, 5
0 ... Axle, 65 ... Hub part, 66 ... Spoke part, 67 ... Rim part, 65A, 71, 75 ... Connection part (partition wall, side wall, side wall), 72, 76 ... Boss part, 73, 77 ... Recessed part (first Recesses, second recesses, 73A, 77A ... Bottom parts (first bottom wall, second bottom wall), 78, 79 ... Opening parts (first opening, second opening), 81 ... Inner hub, 82 ... Outer hub.

Claims (3)

[Claims] 1. A motorcycle wheel comprising a hub portion rotatably supported by an axle and a rim portion connected to the hub portion via a spoke portion, wherein the hub portion is an inner hub arranged on the axle side. And an outer hub arranged on the outer peripheral side of the inner hub and connected to the spokes, and a connecting portion integrally connecting the inner hub and the outer hub.The inner hub and the outer hub are formed with an axial recess and an opening. A wheel for a motorcycle, characterized in that two kinds of recesses, each of which has a bottom portion and a bottom portion, which are formed on opposite sides, are arranged alternately in the circumferential direction. 2. The wheel for a motorcycle according to claim 1, wherein a thick boss portion is formed at the bottom of each of the two types of recesses. 3. The motorcycle wheel according to claim 1, wherein the two kinds of recesses are tapered from the bottom to the opening.